package com.rainbowBoot.utils;

import java.awt.BasicStroke;
import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Random;

import javax.imageio.ImageIO;

/**
 * 随机生成验证码图片 图片长宽默认70 * 35
 * @author 小熊
 *
 */
public class VerificationCodeUtil {
	// 图片宽度
	private static int width = 70;
	// 图片高度
	private static int height = 35;
	private static final Random r = new Random();
	// 验证码上的文本
	private static String text ;
	
	/**
	 * 设置宽度
	 * @param width
	 */
	public static final void setWidth(int width) {
		VerificationCodeUtil.width = width;
	}
	
	/**
	 * 设置高度
	 * @param height
	 */
	public static final void setHeight(int height) {
		VerificationCodeUtil.height = height;
	}
	
	/**
	 * 随机生成颜色
	 * @return
	 */
	private static final Color randomColor () {
	    int red = r.nextInt(150);
	    int green = r.nextInt(150);
	    int blue = r.nextInt(150);
	    return new Color(red, green, blue);
	}
	
	/**
	 * 随机生成字体
	 * @return
	 */
	private static final Font randomFont () {
		// {"宋体", "华文楷体", "黑体", "华文新魏", "华文隶书", "微软雅黑", "楷体_GB2312"}
		String[] fontNames  = {"宋体", "华文楷体", "黑体", "华文新魏", "华文隶书", "微软雅黑", "楷体_GB2312"};
	    int index = r.nextInt(fontNames.length);
	    String fontName = fontNames[index];//生成随机的字体名称
	    int style = r.nextInt(4);//生成随机的样式, 0(无样式), 1(粗体), 2(斜体), 3(粗体+斜体)
	    int size = r.nextInt(5) + 24; //生成随机字号, 24 ~ 28
	    return new Font(fontName, style, size);
	}
	
	/**
	 * 画干扰线
	 * @param image
	 */
	private static final void drawLine (BufferedImage image) {
		// 干扰线条数
		int num = 6 * (width * height / (70 * 35));
		Graphics2D g2 = (Graphics2D)image.getGraphics();
		for(int i = 0; i < num; i++) {//生成两个点的坐标，即4个值
		    int x1 = r.nextInt(width);
		    int y1 = r.nextInt(height);
		    int x2 = r.nextInt(width);
		    int y2 = r.nextInt(height); 
		    g2.setStroke(new BasicStroke(1.5F)); 
		    g2.setColor(randomColor()); //随机生成干扰线颜色
		    g2.drawLine(x1, y1, x2, y2);//画线
		    }
	}
	
	/**
	 * 随机生成字符
	 * @return
	 */
	private static final char randomChar () {
		// 可选字符
		String codes  = "23456789abcdefghjkmnopqrstuvwxyzABCDEFGHJKMNPQRSTUVWXYZ";
	    int index = r.nextInt(codes.length());
	    return codes.charAt(index);
	}
	
	/**
	 * 创建BufferedImage
	 * @return
	 */
	private static final BufferedImage createImage () {
	    BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB); 
	    Graphics2D g2 = (Graphics2D)image.getGraphics(); 
	    g2.setColor(new Color(255, 255, 255));
	    g2.fillRect(0, 0, width, height);
	     return image;
	}
	
	/**
	 * 得到验证码
	 * @return
	 */
	private static final BufferedImage getImage () {
	    BufferedImage image = createImage();//创建图片缓冲区 
	Graphics2D g2 = (Graphics2D)image.getGraphics();//得到绘制环境
	StringBuilder sb = new StringBuilder();//用来装载生成的验证码文本
	// 向图片中画4个字符
	for(int i = 0; i < 4; i++)  {//循环四次，每次生成一个字符
	    String s = randomChar() + "";//随机生成一个字母 
	    sb.append(s); //把字母添加到sb中
	    float x = i * 1.0F * width / 4; //设置当前字符的x轴坐标
	    g2.setFont(randomFont()); //设置随机字体
	    g2.setColor(randomColor()); //设置随机颜色
	    g2.drawString(s, x, height-5); //画图
	}
	text = sb.toString(); //把生成的字符串赋给了this.text
	drawLine(image); //添加干扰线
	    return image;        
	}
	
	/**
	 * 返回验证码图片上的文本
	 * @return
	 */
	public static final String getText () {
	    return text;
	}
	
	/**
	 * 保存图片到指定的位置
	 * @param out
	 * @throws IOException
	 */
	public static final void output (OutputStream out) 
	            throws IOException {
	    ImageIO.write(getImage(), "JPEG", out);
	}
}
